ERJ Express. Published on January 22, 2015 as doi: 10.1183/09031936.00146914 LETTER IN PRESS | CORRECTED PROOF
Serious adverse events during a 6-min walk test in patients with pulmonary hypertension To the Editor: The 6-min walk test (6MWT) is well standardised and, as per current guidelines, is deemed safe to perform in a range of patients [1]. In pulmonary arterial hypertension (PAH), 6-min walk distance (6MWD) is an important predictor of mortality and morbidity [2]. Moreover, changes in the 6MWD have been the primary end-point of most pivotal randomised controlled trials that have assessed the clinical response to specific pharmacological therapies in PAH [2]. To date there have been no published reports about the serious adverse events associated with the 6MWT, e.g. death, life-threatening events, inpatient hospitalisation or prolongation of existing hospitalisation, persistent or significant incapacity, and substantial disruption to the ability to conduct normal life [3]. Perhaps the best reported study that supports the safety of the 6MWT is that of ENRIGHT et al. [4], which was performed in over 2000 elderly subjects (77±4 years of age) with a range of comorbidities. The authors reported no serious adverse events during the 6MWT, and whilst some participants stopped the test with chest pain, no emergency evaluation or therapy was required. More recently, in a review of 741 stable lung disease patients, only 43 (6%) had an adverse event during or immediately after the 6MWT [5]. Notably none of these adverse events would have been classified as serious, with the majority (n=35) being instances in which the test was stopped because patient arterial oxygen saturation measured by pulse oximetry (SpO2) dropped below 80%. Here we report three separate cases of serious adverse events (including one death) during or immediately after 6MWT in which pulmonary hypertension (PH) patients lost consciousness and required emergency attendance. All tests were conducted in a tertiary PH unit located at a large specialist thoracic hospital in Australia where 15–25 6MWTs are performed each week. In Australia, the 6MWT is routine practice as a requirement for an ongoing pharmaceutical benefit scheme. As per unit policy, the attending physiotherapist walks with the patient and monitors symptoms, heart rate (HR) and SpO2 every minute during the test. Criteria for stopping the test were excessive dyspnoea, diaphoresis, pallor, chest pain, leg pain, dizziness or light-headedness, and an HR 170 beats·min−1 [1]. Note that the unit does not apply a minimal SpO2 for stopping the test as many PH patients (e.g. those with congenital heart disease) tend to desaturate substantially during the test without accompanying adverse symptoms. Oxygen therapy is administered if resting SpO2 is
Serious adverse events during a 6-min walk test in patients with pulmonary hypertension To the Editor: The 6-min walk test (6MWT) is well standardised and, as per current guidelines, is deemed safe to perform in a range of patients [1]. In pulmonary arterial hypertension (PAH), 6-min walk distance (6MWD) is an important predictor of mortality and morbidity [2]. Moreover, changes in the 6MWD have been the primary end-point of most pivotal randomised controlled trials that have assessed the clinical response to specific pharmacological therapies in PAH [2]. To date there have been no published reports about the serious adverse events associated with the 6MWT, e.g. death, life-threatening events, inpatient hospitalisation or prolongation of existing hospitalisation, persistent or significant incapacity, and substantial disruption to the ability to conduct normal life [3]. Perhaps the best reported study that supports the safety of the 6MWT is that of ENRIGHT et al. [4], which was performed in over 2000 elderly subjects (77±4 years of age) with a range of comorbidities. The authors reported no serious adverse events during the 6MWT, and whilst some participants stopped the test with chest pain, no emergency evaluation or therapy was required. More recently, in a review of 741 stable lung disease patients, only 43 (6%) had an adverse event during or immediately after the 6MWT [5]. Notably none of these adverse events would have been classified as serious, with the majority (n=35) being instances in which the test was stopped because patient arterial oxygen saturation measured by pulse oximetry (SpO2) dropped below 80%. Here we report three separate cases of serious adverse events (including one death) during or immediately after 6MWT in which pulmonary hypertension (PH) patients lost consciousness and required emergency attendance. All tests were conducted in a tertiary PH unit located at a large specialist thoracic hospital in Australia where 15–25 6MWTs are performed each week. In Australia, the 6MWT is routine practice as a requirement for an ongoing pharmaceutical benefit scheme. As per unit policy, the attending physiotherapist walks with the patient and monitors symptoms, heart rate (HR) and SpO2 every minute during the test. Criteria for stopping the test were excessive dyspnoea, diaphoresis, pallor, chest pain, leg pain, dizziness or light-headedness, and an HR 170 beats·min−1 [1]. Note that the unit does not apply a minimal SpO2 for stopping the test as many PH patients (e.g. those with congenital heart disease) tend to desaturate substantially during the test without accompanying adverse symptoms. Oxygen therapy is administered if resting SpO2 is
